This invention is related to the field of custom forming and installation of acrylic counter tops. In particular, the invention is directed to a method and apparatus for molding preformed acrylic sheets into selected shapes.
Acrylic material and acrylic composites in the form of thick boards have long been used successfully as countertops and the like in kitchens and bathrooms. These "solid surface" materials have an attractive finish which can withstand exposure to a wide range of temperatures and materials without being damaged. Acrylic, however, is very difficult to mold after it has been formed. Consequently, it has been required that the counter tops and the like be formed in a shop. Further, any irregular surfaces, such as curves, rounded edges and backsplashes, must be separately formed and then glued into position on the acrylic boards. To employ acrylic materials at all, the space may needed to be built out to match the material, rather than forming the material to match the space. This need for labor and special forming, as well as the cost of the acrylic itself, has made the cost of using acrylic materials prohibitive.
Recently, acrylic materials have become available in thinner sheets, ranging from 1/8 inch to 3/4 inch. The sheets are intended to be mounted onto wooden counters as a laminate layer, thereby forming a counter top which has the appearance and some of the increased durability of the solid surface counter tops but at a reduced cost. These sheets are not intended to be molded into curved shapes, like certain plastic laminates. Consequently, curved portions and backsplashes must still be separately formed and then glued together, as with traditional acrylic boards.
Attempts have been made to post-form these sheets using techniques employed for laminate sheets of other materials, such as plastic sheeting. Typically such efforts include taking the portion of the sheet intended to be formed and placing it in a closed-walled, convection oven. The convection oven is operated at a temperature of about 400.degree. F. and the portion of the sheet is left in there for several minutes until the laminate sheet becomes flexible. This flexible portion is then molded to a selected shape which it retains after cooling.
Although the thin acrylic sheets are rendered flexible such that they can be molded when employing such techniques, these attempts have ultimately proved unsuccessful. Unlike the traditional laminate materials, the acrylic sheets tend to discolor (turning cloudy or whitish) when they are molded and cooled in this manner. Further, after a portion of the acrylic sheet has been heated and cooled, it becomes brittle where it joins the portion which has not been heated such that the acrylic sheet cannot be cut without splintering or shattering.
The instant invention includes methods and apparatus which overcome these difficulties, allowing for the post-forming of acrylic sheets without discoloration. The formed sheets can be cut to fit the installation space without splintering the edges. Consequently, the space itself does not necessarily need to be built out or modified to the acrylic sheet.